1. Field of the Invention
The present invention relates to elastic wave devices and elastic wave module devices.
2. Description of the Related Art
Elastic wave devices such as surface acoustic wave devices have been widely used in filters and the like, for example. Japanese Patent No. 4811232 discloses a surface acoustic wave device including a piezoelectric substrate on the surface of which an IDT (interdigital transducer) electrode is provided, and a cover member provided above the piezoelectric substrate so as to cover the IDT electrode. It is disclosed in Japanese Patent No. 4811232 that a protection member whose elastic modulus is smaller than that of a mold resin is provided on the cover member so as to increase durability against the pressure impact applied to the surface acoustic wave device during molding of the surface acoustic wave device to be used in an elastic wave module device.
Also in the surface acoustic wave device disclosed in Japanese Patent No. 4811232, there is a case where the cover member is deformed by the pressure applied thereto during the molding resulting in making contact with the IDT electrode or the like, whereby there arises a problem that the IDT electrode is damaged and so on.